17.5. Conclusion

If you've used relational databases extensively, you might be tempted
to perform all your JDO queries with SQL. Try to resist this
temptation. SQL queries tie your application to the particulars of
your current table model and database vendor. If you stick with JDOQL,
on the other hand, you can port your application to other schemas and
database vendors without any changes to your code. Additionally,
most JDO implementations already produce highly optimized SQL from
your JDOQL filters, and many are able to cache JDOQL query results
for added performance.